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-   -   Know any good capacitor brands? (http://www.physicsforums.com/showthread.php?t=210654)

chrisalviola Jan23-08 08:11 PM

know any good capacitor brands?
 
in my power supply its the first semiconductor that becomes defective, it must be the brand or its not a good quality, I need to buy a new one and solder it, is there any good brands out there or is it important?

chroot Jan23-08 08:28 PM

It's not generally important. Just make sure it's an exact fit by specifications.

- Warren

chrisalviola Jan23-08 08:32 PM

the capacitor value is 2200uf 10v, can I use more than 10v and still produce the same results?

eeboy Jan23-08 09:41 PM

The rating on the cap must be greater than or equal to 10V. The larger the better (greater margin). However, as the voltage rating increases the physical size will also increase.

Also, make certain you choose the same type of capacitor. Based on the value I can pretty much tell you you are dealing with an electrolytic capacitor. When replacing electrolytics you must observe the proper polarity.

NoTime Jan23-08 10:06 PM

If you have a switching power supply then the electrolytic must be rated for this application. You might try Digikey, I recall they have a fair selection of this class of electrolytic .

If the power supply is just rectified AC stepdown transformer you can normally use just about any electrolytic that matches the voltage and capacitance.

chrisalviola Jan24-08 09:58 AM

Quote:

Quote by NoTime (Post 1582460)
If you have a switching power supply then the electrolytic must be rated for this application.

yes this is a swithing power supply for my pc, this means I can use a higher rated voltage for my capacitor? like >=10v but same rate of "uf", would this produce the same output voltage?

edmondng Jan24-08 10:45 AM

yes. higher rated voltage is better but you pay more $$ and size is bigger. so if the voltage is only 5v, anything like 10v/16v rating works. why pay and use 100v or 1000v size capacitor?

some capacitor features may be important if you are dealing with rf but for most usage it is not a problem

chroot Jan24-08 11:39 AM

The voltage rating is the largest voltage the capacitor can tolerate without being damaged. Obviously, higher is better, so you can replace the cap with a new one of equal or greater voltage capability.

- Warren

berkeman Jan24-08 12:19 PM

Quote:

Quote by chrisalviola (Post 1582861)
yes this is a swithing power supply for my pc, this means I can use a higher rated voltage for my capacitor? like >=10v but same rate of "uf", would this produce the same output voltage?

If it is on the output of a switching power supply, then the ESR rating for the cap (equivalent series resistance) can be an issue. The higher the ESR, the higher the ripple voltage at the power supply output, which can cause issues in the circuit being powered. Also, the value of the ESR affects the stability margin of the switching power supply. You need to read the specifications/datasheet for the capacitor that you are replacing, and match the ESR the best that you can. In general, a lower ESR is better.

Corneo Jan24-08 09:49 PM

Sometimes just putting a 10V rated cap on a 7V line isn't enough. This is something I deal with at work. You might want to look into capacitor deratings as well.


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